The two young infielders are putting up eye-popping numbers

Every week, Sporting News’ Ryan Fagan will take a deeper look at the players making on-the-field headlines—both good and bad—with the help of advanced baseball metrics. Unless otherwise specified, statistics have been gathered from baseball-reference.com and fangraphs.com, two thoroughly indispensable websites.

This week, we’ll look at two of the best young defensive players in the game with the help of a couple of the most widely used advanced defensive metrics. One thing to keep in mind: While defensive statistics have come a long, long way over the past 20 years, they’re still not as definitive as the absolutes provided by offensive and pitching statistics. It’s best to look at multiple years of a player’s data (when available) before drawing any final conclusions (all stats through Sunday).

Simmons, a second-round pick in the 2010 draft, was rated by Baseball America as the Braves’ top position prospect heading into the 2012 season (fourth overall), based mostly on his strength with the glove. He’s proven those projections accurate, and because of that prowess, he’s become an irreplaceable part of the Atlanta lineup. He’s been streaky with the bat this season—.534 OPS in June, .837 in July and .640 in August—but he’s provided some power (12 homers) while hitting mostly near the top of the Braves’ batting order.

What DRS is: Defensive Runs Saved. Using data gathered by Baseball Info Solutions and calculated by The Fielding Bible, DRS is an attempt to measure a defender’s overall value and translate that value into a “runs saved” statistic. Basically, how many runs did the defender prevent with his glove? Here’s a much more detailed explanation from Fangraphs. DRS is a cumulative stat, so full-season totals can’t be compared to DRS totals, for example. As a point of comparison, in the past decade, there have been a dozen players compile a DRS of at least 30; Adam Everett’s 34 for the Astros in 2006 is the highest total (for any position) in that span heading into this season.

What this means: Read that previous line again. Adam Everett’s 34 DRS for the Astros in 2006 is the highest total (for any position) in that span. Simmons is at 39, with almost a month left in the season. So, yes, he’s been pretty outstanding as Atlanta’s shortstop. Simmons, who turns 24 on Wednesday, has outstanding range even for a shortstop and a big arm that he displays on a nightly basis. Here’s another way to look at it—of the 43 defenders who have played at least 250 innings at shortstop, only one has a DRS of higher than 11. That’s Minnesota’s Pedro Florimon, who checks in at 17. That’s a huge gap.

Machado has been a regular on highlight reels because of his glove this season, and his defensive metrics tell us those individual plays aren’t random, fluke events. He’s been so good at the hot corner that it’s hard to remember he was a shortstop in the minors and was expected to play there for a long time with the Orioles. Machado, the No. 3 overall pick of the 2010 draft, has cooled off at the plate after an outstanding first half (.310 average, .807 OPS), but he’s still hitting .298 this season with 46 doubles and a dozen home runs.

What UZR is: Ultimate Zone Rating. Much like DRS, UZR uses data from Baseball Info Solutions and is an attempt to measure a player’s total defensive value. For an infielder, UZR uses factors like a player’s range, his propensity to turn double-plays and whether he commits more or fewer errors than an average defender at his position. As a point of reference, Adrian Beltre’s 25.9 UZR in 2004 is the best mark for an infielder during the past decade heading into this season.

What this means: Much like Simmons at shortstop, Machado is doing amazing things with the glove this season. You might have already noticed that his 26.8 UZR is better than Beltre’s 25.9, but if not, we’ll point it out again. Beltre deserves his reputation as one of the best defensive third basemen in this era, and Machado is outperforming Beltre’s best defensive season (statistically) as a 21-year-old rookie. At his secondary position. Yep.